ISO 15339 Prin.ng from digital data across mul.ple technologies " Mr. David McDowell March 15, 2012
The real title" An introduction to ISO 15339; " The history and genesis of ISO 15339; " why the printing industry needs it; " what it entails; " who will embrace it" 2
Where we are today" 3
Current Printing Standards" ISO 12647, Graphic technology - Process control for the manufacture of half-tone colour separations, proof and production prints " Started in ISO TC130 in 1991 (first part published 1996)" Process control aims" Colour of the solids and 2-colour overprints" TVI and Grey balance" Tone value sum" Substrate (colour and gramage)" Initially based on film workflow but evolved to include digital data." 4
Current Printing Standards" ISO 12647" Part 1: Parameters and measurement methods" Part 2: Offset lithographic processes" Part 3: Coldset offset lithography on newsprint" Part 4: Publication gravure printing" Part 5: Screen printing" Part 6: Flexographic printing" In 1996 these represented a major step forward in definition of printing aims for the industry" Last revision published in 2007" Proposed revision of Parts 1-6 currently underway" 5
ISO 12647 How used?" Designer/client picks printing condition from ISO 12647 based on paper and process to be used " Validation prints and proofs based on aims of ISO 12647 as interpreted by non-standardized characterization data from various trade groups." Calibrate press to achieve solids and TVI for printing condition of ISO 12647" Produce OK print to match the proof" Print " While printing verify that solids and TVI are within variation tolerances of ISO 12647 and/or make printing match the proof" " 6
Printing in 2012" The full potential of color management and reference printing conditions cannot be realized by further adapting 12647 " ISO 15339 represents a new approach to printing definition based on:" Using reference color characterization data " Being process independent " Providing data adjustment for variations in paper color" 7
Lets look at ISO 15339" 8
The History" The March/April 1999 issue of IPA Prepress Bulletin had an article titled Reference Printing Conditions - What Are They & Why Are They Important?! Key point was Some of us believe that a different, and better, approach is available one that will allow us to accommodate the needs of the press, and, in fact, give the printer more freedom and control over the press; one that will simplify the interface between prepress and printing; and one that will allow us all to produce better, more consistent output in a more cost effective method. " 9
The Basic Concept" Standardize characterization data NOT process control data" Have a limited set of Characterized Reference Printing Conditions (CRPC) that differ in gamut" Use these as the nodal point between design, prep, proofing and printing" Provide some mechanism to adjust CRPC for modest paper changes" 10
A New View From a 1999 presentation" Proofing Prin,ng Reference Prin,ng Condi,ons Pre- Press Data Exchange 11
Characterization Data" Is the relationship between input CMYK (or virtual CMYK) data and the color on the printed sheet." Typically defined in terms of 1617 patches of ISO 12642-2 (IT8.7/4) target" Outer shell: Determined by paper, ink, process capability" Within gamut portion adjustable using color management, tone curves, etc (ISO TS 10128)" 12
An Additional Key Issue" CRPCs should (can) be process agnostic!" Since it s creation in 1995, TR001 (SWOP) has applied to both offset and gravure publications" All proofing (regardless of proofing process) is based on matching characterization data " Packaging matches color across processes" 13
Why Worry" Proliferation of data sets is out of control and NO data sets are standardized" FOGRA now has over 50 sets of characterization data" US has 6 with several prototype data sets" Japan has at least 4" Proposed new ISO 12647 series has 18 new print conditions (at least 1 data set each)" All claiming some sort of compliance to ISO 12647" 14
What ISO 15339 Proposes" 1. Standardize characterization data, not process control data" 2. Limited number of default reference characterization data sets (7)" 3. Allow use of other data sets with prior agreement " 4. Provide mechanism to adjust for paper changes including OBA" 5. Provide consistent tone reproduction aims across data sets" 15
Benefits to Industry" Print buyer " Easier to specify desired appearance" Process independent" Universal global applicability" Designer/Prep house" Fewer profiles/characterization data " Later binding to actual reproduction process" Greater flexibility in substrate specification" 16
Benefits to Industry" Printer" More meaningful and logical certification procedures" Simpler communication of aims" Ability to adjust for substrate effects (including OBA)" Common aims for proofing and printing" More compatible with management systems requirements" 17
Some Details" 18
Reference Printing Condition" What is a Reference Printing Condition?" The specific outer gamut to be achieved and a reference tabulation of the CMYK to printedcolor relationship of within-gamut data" Within-gamut data may be (usually is) for an ideal (virtual) printing system" Used for data exchange and reference " 19"
The 7 ISO 15339 CRPCs" CRPC! CRPC name! 1" ColdsetNews" 2" HeatsetNews" 3" PremUncoated" 4" SuperCal" 5" PubCoated" 6" PremCoated" 7" Extra Large" 20
The 7 ISO 15339 RPC gamuts" 110 90 70 50 30 10-80 -60-40 -20 0 20 40 60 80-10 7 6 5 4 3 2 1-30 -50-70 21"
ISO 15339 CRPC Characteristics" Each reference printing condition based on different outer gamut" Comprises a minimal set that effectively covers the range of print and paper conditions" Represents colour reproduction of modern commercial printing that uses ISO 2846 inks" Consistent with colorimetry of primary, two colour and three colour solids in historical press test data for various conditions (ISO 12647)" Neutral CMY and K tonal curves that closely match each other from paper though mid-tone" Neutral CMY and K tonal curves that each transition smoothly from mid-tone to 3c solid" Defined gray balance that transitions smoothly the from paper color to that of the 3c solid for specified CMY triplets" 22
Substrate Adjustment" Tristimulus Correction Method" Uses CIE XYZ values of new substrate to adjust CIE XYZ values of reference characterization data to predict what same printing would be on the new substrate" Practical test shows it works equally well for changes in substrate resulting from a basic shade change or change in OBA level" May also work to correct for instrument deficiencies " Simple computation documented in ISO 13655" Provides new aims for all CMYK data points (including solids and neutrals)" 23
Workflow" Design Selects aim characterization data based on expected paper and printing process Content Data Proofing Content Data CRPC (7 sets) Printing Substrate Adjustment 24
ISO TS 10128" A technical specification called: Graphic technology Methods of adjustment of the colour reproduction of a printing system to match a set of characterization data! Assumes outer gamuts are correct" Adjusts within-gamut data by one of three methods" Matching of tone value curves to develop 4 1-D transforms" Use of near-neutral scales to develop 4 1-D transforms" Use of CMYK to CMYK multi-dimensional transforms (colour management device link transform)" Can be used to support printing based on either " ISO 15339 or ISO 12647 " 25
Added Possibility" Paper manufacturers (we hope) will provide cross- reference table that lists for each paper" Process compatibility " Max ISO 15339 gamut supported for each "process (with standard inks)" Aim CIEXYZ values (white point) for each paper measured using M1 with white backing" 26
Where do we go from here?" 27
Current road-blocks/obstructions" European trade associations have a huge investment in providing printer certification to ISO 12647" Many printers have been sold the idea that if they match solids and TVI they will print correctly" Europeans have worked hard to taint ISO 15339 as being US and based on GRACoL G7 - the fear of the unknown " All European characterization data today is private no public input or review" 28
Current road-blocks/obstructions" CRPCs of ISO 15339 replace TVI aims with gray balance and neutral scale tone reproduction aims" " 29
Who will be adopters" G7 certified printers are much more open to the concepts of ISO 15339 " G7 certified printers" US " South America -" Asia -" Europe " Printers using color managed workflows" Publication printers" Package printers" International consumer products companies" "" 30
Differences" ISO 12647 (Historically + today)" Printing aims based on real press & real process" Process and substrate specific" Match selected process control aims " Solids, TVI, Mid-tone spread" ISO 15339 (Today and into the future)" Define color desired from printing device (Characterization data)" Family of seven default CRPCs (virtual devices)" Selected aim CPRC used by all segments of the workflow" Printer matches selected CRPC (adjusted if necessary for substrate) using printing device characteristics and data adjustment tools (ISO TS 10128)" Process control (including aims) responsibility of printer" 31
Q&A Thank you for your a3en5on.